Sluggish working of Outlook creates too much trouble for its users by hampering their operations. So, in this case best choice is to use some tool to recover corrupted PST .If your PST already corrupted then use Outlook recovery tool to repairs PST first then try Split PST to divide large PST into smaller parts to avoid further corruption. The software kept all its META DATA like cc, bcc, attachments, sent/receive etc intact during the process.